http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55341
--- Comment #21 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-12-19
08:52:43 UTC ---
(In reply to comment #17)
> For whatever reason the fortran code is touching asan's shadow:
> Address 0x1ffff6742e2c is located in the high shadow area.
>
> What is __qs_environment_MOD_qs_init doing?
> Is it normally touching that region of address space?
Ah, it could be the clearing of the stack shadow area. If there are just a few
stores needed or if it is non-contiguous enough,
clear_storage (shadow_mem, GEN_INT (last_size >> ASAN_SHADOW_SHIFT),
BLOCK_OP_NORMAL);
is expanded as piece-wise stores, but if the shadow memory area is too big,
depending on the target CPU it can be also expanded as memset function call.
So, to fix this, either libasan should for memset ignore any diagnostics for
stores into shadow memory area, or I'll need to force somehow that memset is
never generated for it, or we could have a non-instrumented memset alternative
in libasan and we could call that.
